- author = "Raja Muhammad Atif Azad",
- title = "A Position Independent Representation for Evolutionary Automatic Programming Algorithms - The Chorus System",
- school = "University of Limerick",
- year = "2003",
- address = "Ireland",
- month = dec,
-
URL = "
http://www.cs.ucl.ac.uk/staff/W.Langdon/ftp/papers/azad_thesis.ps.gz",
- size = "212 pages",
- keywords = "genetic algorithms, genetic programming, Chorus System, Grammatical Evolution",
-
abstract = "We describe a new position independent encoding
system, Chorus, for grammar based Evolutionary
Algorithms. This scheme is coarsely based on the manner
in nature in which genes produce proteins that regulate
the metabolic pathways of the cell. The phenotype is
the behaviour of the cells metabolism, which
corresponds to the development of the computer program
in our case. In this procedure, the actual protein
encoded by a gene is the same regardless of the
position of the gene within the genome.
We show that the Chorus system has a very convenient Regular Expression type schema notation that can be used to describe the presence of various phenotypic traits. This notation is used to demonstrate that massive areas of neutrality can exist in the search landscape, and the system is also shown to be able to dispense with large areas of the search space that are unlikely to contain useful solutions.
The searching capability of the system is exemplified by its application on a number of proof of concept problems, where the system has shown comparable performance to Genetic Programming and Grammatical Evolution and, in certain cases, it has produced superior results.
We also analyse the role of the crossover in the Chorus System and conclude by showing its application on a real world problem from the blood flow domain.",
- notes = "Supervisor: Conor Ryan",
